Q: What are the factor combinations of the number 399,817?

 A:
Positive:   1 x 39981711 x 3634719 x 21043209 x 1913
Negative: -1 x -399817-11 x -36347-19 x -21043-209 x -1913


How do I find the factor combinations of the number 399,817?

Unfortunately, there's not simple formula to identifying all of the factors of a number and it can be a tedious process when trying to identify the divisors of larger numbers. To find the factor combinations of the number 399,817, it is easier to work with a table - it's called factoring from the outside in.

Outside in Factoring

We start by creating a table and writing 1 on the left side and then the number we're trying to find the factors for on the right side in a table. Then, below that, write the numbers as a negative as well.

1 399,817
-1 -399,817

Why are the negative numbers included?

When you multiply two negative numbers together, you get a positive number. That means both the positive and negative numbers are factors of 399,817.

Example:
1 x 399,817 = 399,817
and
-1 x -399,817 = 399,817
Notice both answers equal 399,817

With that explanation out of the way, let's continue. Next, we take the number 399,817 and divide it by 2:

399,817 ÷ 2 = 199,908.5

If the quotient is a whole number, then 2 and 199,908.5 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.

Here is what our table should look like at this step:

1 399,817
-1 -399,817

Now, we try dividing 399,817 by 3:

399,817 ÷ 3 = 133,272.3333

If the quotient is a whole number, then 3 and 133,272.3333 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.

Here is what our table should look like at this step:

1 399,817
-1 -399,817

Let's try dividing by 4:

399,817 ÷ 4 = 99,954.25

If the quotient is a whole number, then 4 and 99,954.25 are factors. In this case, the quotient is not a whole number. Don't write anything down and try the next divisor.

Here is what our table should look like at this step:

1 399,817
-1 399,817
Keep dividing by the next highest number until you cannot divide anymore.

If you did it right, you will end up with this table:

111192091,91321,04336,347399,817
-1-11-19-209-1,913-21,043-36,347-399,817

More Examples

Here are some more numbers to try:

Try the factor calculator

Explore more about the number 399,817:


Ask a Question